Consider the (REF )-(REF ) system with \(K_{d}=20\) ,
\(K_{p}=100\) , \(K_{i}=1000\)  and varying \(F_{c}=\lbrace 50, 75, 100\rbrace \) .
The initial values are assigned as \(x(0)=\lbrace 0, -1.1, 0\rbrace \) ,
corresponding to a classical positioning task for the feedback-
controlled system (REF ). Note that
\(|x_{2}(0)|>F_{c}K_{p}^{-1}\)  so that the trajectories start
outside of \(S_{0}\)  and are, therefore, inherently in the slipping phase.
The transient and convergence responses for all three Coulomb
friction values are shown opposite to one another in Figure
REF , cf. qualitatively with an experimental convergence
pattern reported in [1]}.
<FIGURE>